Dental caries is initlated by the demineralisation of hard tissue of the teeth by organic acids produced from fermentation of dietary sugar by dental plaque odontopathogenic bacteria.
Dental caries is still a major public health problem and restored tooth surfaces can be susceptible to further dental caries around the margins of the restoration.
Casein phosphopeptide-amorphous calcium phosphate complexes (CPP-ACP) and CPP-stabillsed amorphous calcium fluoride phosphate complexes (CPP-ACFP) in solution have been shown to prevent enamel deminerallsation and promote remineralisation of enamel subsurface lesions in animal and human in situ caries models [Reynolds 1997 patent application, PCT/AU98/00160].
The active CPP have been specified in the U.S. Pat. No. 5,015,628 and include peptides Bos αs1-casein X-5P (f59-79) [1], Bos β-casein X-4P (f1-25) [2], Bos αs2-casein X-4P (f46-70) [3] and Bos αs2-casein X-4P (f1-21) [4] as follows:    [1] Gln59-Met-Glu-Ala-Glu-Ser(P)-Ile-Ser(P)-Ser(P)-Ser(P)-Glu-Glu-Ile-Val-Pro-Asn-Ser(P)-Val-Glu-Gin-Lys79. αs1(59-79)    [2] Arg1-Glu-Leu-Glu-Glu-Leu-Asn-Val-Pro-Gly-Glu-Ile-Val-Glu-Ser(P)-Leu-Ser(P)-Ser(P)-Ser(P)-Glu-Glu-Ser-Ile-Thr-Arg25. β(1-25)    [3] Asn46-Ala-Asn-Glu-Glu-Glu-Tyr-Ser-Ile-Gly-Ser(P)-Ser(P)-Ser(P)-Glu-Glu-Ser(P)-Ala-Glu-Val-Ala-Thr-Glu-Glu-Val-Lys70. αs2(46-70)    [4] Lys1-Asn-Thr-Met-Glu-His-Val-Ser(P)-Ser(P)-Ser(P)-Glu-Glu-Ser-Ile-Ile-Ser(P)-Gin-Glu-Thr-Tyr-Lys21. αs2(1-21)
These peptides stabilise novel forms of very soluble amorphous calcium phosphate and amorphous calcium fluoride phosphate [Reynolds 1997 patent application, PCT/AU98/00160].
Glass ionomer cements (GICs) are water-based, tooth coloured and chemically adhesive materials used in dentistry as bases and restorations. Microleakage around restorations remains a significant problem, which can lead to caries of the underlying tooth tissues (Bergenholtz et al., 1982; Davis et al., 1993; Pachuta and Meiers, 1995). However, GICs are ion-releasing materials and the incorporation and slow release of fluoride ions from the cement provides a significant anticariogenic property (Forss, 1993; Williams et al., 1999)
Although H would be expected that inclusion of CPP-ACP into a GIC would result in the incorporation of the calcium ions into the GIC matrix making them unavailable, surprisingly, we have discovered that incorporation of CPP-ACP into a standard, commercially-available GIC resulted in a GIC with unexpected superior properties in terms of microtensile bond strength. Comprehensive strength and ion-release. In fact, surprisingly the GIC containing CPP-ACP was able to significantly remineralize the underfying dentine whereas the standard GIC could not. These results form the basis of this invention which is novel dental restorative materials containing CPP-ACP or CPP-ACFP with superior physicochemical and anticariogenic properties.